Air conditioning apparatus has been devised heretofore to artificially treat air in buildings to render the living conditions to persons within the building more confortable and heathful, or to ensure better conditions for the production and storage of products or materials.
Depending upon the environment at a specific installation, air conditioning generally involves temperature control, humidity control, ventilation and cleaning.
Heretofore, to provide ventilation, fresh air has been introduced into the building while foul or used air has been expelled or exhausted therefrom. When the outside air temperature was lower than the temperature at which air in the building was to be maintained, the fresh air, or a mixture of fresh air and return air from the building was heated. Consequently, air exhausted from the building was warmer than the fresh air drawn into the building resulting in loss of substantial energy from the facility.
During summer months when temperature outside the building was higher than the temperature to be maintained inside the building, the energy required for cooling the air, which was subsequently exhausted from the building, was wasted.
Regenerators have been employed in steam generating apparatus to reclaim some heat which would otherwise be lost from flue gas and transferring the heat to air required for combustion of fuel. Regenerators have also been used to extract heat from steam exhausted from a turbine and transferring the heat to feed water delivered to a boiler in an effort to minimize heat dissipation from the system.
Thermal regeneration devices have been employed heretofore to transfer heat between fresh air and exhaust air streams in conjunction with heating and air conditioning systems. However, such thermal regenerator apparatus has enjoyed only very limited success because the rate of heat transfer between the exhaust air and the fresh air has been very low and inconsistent.